The present invention broadly relates to an apparatus for transporting flat products, especially printed products, arriving in an imbricated product formation.
In its more specific aspects the present invention relates to a new and improved construction of apparatus for transporting continuously arriving flat products, which apparatus is of the type comprising feeding or infeed means for feeding the printed products to a transport means or device having the same transport direction as the infeed means. Gripper units are arranged in spaced relationship at the transport means and serve to take over the printed products supplied thereto and to hold the same at the leading edges thereof for further transport. At the transfer region the conveying path of the products supplied by the feeding or infeed means forms an acute angle with the travel path of the gripper units of the transport means.
In a transport apparatus of such type suitable measures must be undertaken to ensure that the gripper units or grippers of the transport means can correctly grip the products delivered by the feeding or infeed means in the direction of movement of the gripper units. In transport means as known, for example, from U.S. Pat. No. 3,955,667, this is achieved by gripper units which are provided with a rearwardly directed, stationary upper clamping tongue or jaw and a movable lower clamping tongue or jaw which is laterally directed in the opened position of the gripper units. For seizing the printed products the lower clamping tongue or jaw is firstly pivoted into a position where it is aligned with the upper clamping tongue or jaw and subsequently is moved towards the upper clamping tongue or jaw. The infeed of the printed products has to be accommodated to the movement of the gripper units such that at the transfer region a respective gripper unit meets the printed product in a correct position. During the course of the pivoting movement the lower clamping tongue or jaw is moved beneath the printed product below the leading edge thereof, so that the seized printed product is firmly clamped when the two mutually aligned clamping tongs or jaws are brought together or closed.
In this state-of-the-art transport apparatus the printed products are taken-over by the transport means in the same mutual position they assume in the product formation supplied by the feeding or infeed means. Thus, the product take-over or transfer occurs neither with mutual alignment of the printed products nor with any compensation for different distances between the products.
It may occur that the distance of one product to the leading product deviates rather markedly from the standard or rated distance. While in such a case the gripper units are still able to grip such product, the latter is held, however, only just between the outermost ends of the clamping tongs or jaws. There is, then, the danger that such product can be unintentionally released from the gripper unit during the subsequent transport of the product due to the insufficient clamping action which thus prevails.